Melt-spun Fe-Co-P-B metglas: structure, crystallization kinetics, magnetic properties

Crystallization kinetics and magnetic properties were studied in series of rapidly solidified metallic glasses Fe80-ξCoξP14B6 with ξ = 25, 32, 35 and 40 at. %. Differential scanning calorimetry (DSC) was employed to determine crystallization temperature and to demonstrate the incubation phenomenon at isothermal annealing. Fitting DSC traces recorded in non-isothermal and isothermal regimes, we obtained the same activation energy Q. It describes atomic transfer across crystal/amorphous interface in Kolmogorov-Johnson-Mehl- Avrami (KJMA) model of the transition of metallic glasses into crystalline state. As-quenched metglas ribbons have amorphous structure and superior soft magnetic properties: coercive field 4 A/m, ac magnetic permeability as high as 110 000 at 60 Hz.